.container {
  position: relative;
  height: 100vh;
  width: 100vw;
  background: #3c3c3c;
}
.container .wrap {
  height: 300px;
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  right: 0;
  margin: auto;
}
.container .wrap ul {
  display: flex;
  justify-content: center;
}
.container .wrap ul li {
  width: 60px;
  height: 60px;
  margin: 10px;
  list-style: none;
  background: #303133;
  box-shadow: 0 5px 5px #000;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}
.container .wrap ul li.cur {
  transform: perspective(360px) translateZ(-30px);
}
.container .wrap ul li span {
  box-shadow: 0 5px 5px #000;
  display: block;
  font-size: 26px;
  background: #303133;
  border: 1px solid #333;
  border-radius: 5px;
  width: 50px;
  height: 50px;
  line-height: 50px;
  color: #fff;
  text-shadow: 0 0 2px #000;
  text-align: center;
}
